Air-fuel mixture ratio control using electrostatic force

Abstract

Electrostatically charged liquid fuel is introduced into a venturi to be atomized therein and is then applied to the combustion chambers of an engine under the control of electrostatic force for properly controlling the air-fuel mixture ratio.

What is claimed is: 
     
       1. Arrangement for use with an internal combustion engine having a plurality of combustion chambers, comprising in combination: means for forming a combustible air-fuel mixture from a liquid fuel;   electrostatic charging means having first and second outputs for supplying first and second electrostatic charges with opposite polarity;   a first electrode connected to the electrostatic charging means for imparting the first charge to the liquid fuel to produce ionized fuel droplets in the combustible air-fuel mixture forming means;   means communicating with the combustible air-fuel mixture forming means for introducing the air fuel mixture into the combustion chambers of the internal combustion engine, said introducing means including a plurality of intake passages; and   means for controlling the air-fuel mixture ratio introduced into said combustion chambers, said controlling means including a plurality of second electrodes provided in the air-fuel mixture introducing means, and means for selectively connecting each of said second electrodes to either of said first and second outputs of said electrostatic charging means, whereby one of said first and second charges is selectively applied to said second electrodes and the amount of ionized fuel droplets introduced into each of said combustion chambers is controlled by means of electrostatic forces.   
     
     
       2. Arrangement as claimed in claim 1, wherein said air-fuel mixture forming means includes a venturi and the first electrode comprises a fuel discharging nozzle protruding into said venturi. 
     
     
       3. Arrangement as claimed in claim 1, wherein the number of the second electrodes is equal to that of the combustion chambers, and at least one of said second electrodes is provided in each of the intake passages. 
     
     
       4. Arrangement as claimed in claim 1, wherein the number of the second electrodes is equal to that of the combustion chambers, and wherein each of the intake passages includes a diverging portion, each of the second electrodes being provided in the vicinity of said diverging portion. 
     
     
       5. Arrangement as claimed in claim 1, wherein said controlling means comprises means for providing that at least one of the second electrodes always receives the first charge and the remainder of the second electrodes always receives the second charge. 
     
     
       6. Arrangement as claimed in claim 5, wherein said controlling means controls the amount of the first and the second charges imparted to the second electrodes in accordance with at least one of the engine operation parameters. 
     
     
       7. Arrangement as claimed in claim 1, wherein said controlling means comprises means for providing that at least one of the second electrodes receives selectively one of the first and the second charges in response to ignition timing of the engine, and the remainder of the second electrodes receives the other charge for controlling the air fuel mixture ratio in the combustion chambers. 
     
     
       8. Arrangement as claimed in claim 7, wherein said controlling means controls each of the magnitudes of the first and the second charges imparted to the second electrodes in accordance with at least one of the engine operation parameters. 
     
     
       9. Arrangement as claimed in claim 1, wherein said controlling means comprises means for providing that at least one of the second electrodes receives alternately one of the first and the second charges in response to ignition timing of the engine, and the remainder of the second electrodes receives the other charge. 
     
     
       10. Arrangement as claimed in claim 9, wherein said controlling means controls each of the magnitudes of the first and the second charges imparted to the second electrodes in accordance with at least one of the engine operation parameters. 
     
     
       11. Arrangement as claimed in claim 1, wherein each of the second electrodes is of cylindrical configuration. 
     
     
       12. Arrangement as claimed in claim 1, wherein each of the second electrodes is a mesh electrode. 
     
     
       13. Arrangement as claimed in claim 1, wherein the number of the second electrodes is less than that of the number of the combustion chambers, each of the second electrodes being provided in the vicinity of said diverging portion. 
     
     
       14. Arrangement as claimed in claim 1, wherein the air-fuel mixture introducing means is bifurcated and then separated to extend to each of the combustion chambers, and wherein the number of the second electrodes is one half of the number of cylinders and each of the second electrodes is provided in the vicinity of the bifurcated portion. 
     
     
       15. Arrangement as claimed in claim 14, wherein there are two second electrodes and one of the two second electrodes always receives the first charge and the other always receives the second charge. 
     
     
       16. Arrangement as claimed in claim 14, wherein there are two second electrodes and one of the two second electrodes receives selectively one of the first and the second charges in response to an engine operation parameter indicative of air-intake processes of the combustion chambers, and the other electrode receives the other charge. 
     
     
       17. Arrangement as claimed in claim 16, wherein said controlling means controls each of the magnitudes of the first and the second charges imparted to the second electrodes in accordance with at least one of the engine operation parameters. 
     
     
       18. Arrangement as claimed in claim 1, further comprising a plurality of exhaust passages, one connected to each of the combustion chambers, and a plurality of exhaust gas sensors provided in the exhaust passages for generating a signal representative of a sensed concentration of a component of exhaust gases, and including means for controlling the voltage applied to the second electrodes in response to the signals from the exhaust gas sensors. 
     
     
       19. Arrangement as claimed in claim 1, wherein the combustible air-fuel mixture forming means includes a venturi, and further comprising a third electrode which is provided in the vicinity of said venturi and connected to the electrostatic charging means for receiving the second charge therefrom. 
     
     
       20. Arrangement as claimed in claim 1, wherein the combustible air-fuel mixture forming means includes a venturi, and further comprising a third electrode which is integral with the venturi and electrically insulated from the remainder of the venturi and connected to the electrostatic charging means for receiving the second charge therefrom. 
     
     
       21. Arrangement as claimed in claim 1, further comprising a fourth electrode arranged in such a manner as to face the first electrode and being connected to the electrostatic charging means for receiving the second charge and for providing corona discharge area between itself and the first electrode. 
     
     
       22. Arrangement as claimed in claim 21, wherein one of the first and the fourth electrodes is provided with at least one sharp edge portion and the other electrode is provided with at least one slit. 
     
     
       23. Arrangement as claimed in claim 22, wherein said air-fuel mixture forming means includes a venturi and fuel discharging nozzle protruding into said venturi and the first and the fourth electrodes are positioned in said fuel discharging nozzle. 
     
     
       24. Arrangement as claimed in claim 22, wherein the air-fuel mixture forming means includes a float bowl, a venturi and a fuel passage extending between the float bowl and the venturi, and the first and the fourth electrodes are positioned in said fuel passage. 
     
     
       25. Arrangement as claimed in claim 1, further comprising a fourth electrode arranged in such a manner as to face the first electrode and being connected to the electrostatic charging means for receiving the second charge and for providing corona discharge area. 
     
     
       26. Arrangement as claimed in claim 25, wherein one of the first and the fourth electrodes is provided with at least one sharp edge portion and the other electrode is provided with at least one slit. 
     
     
       27. Arrangement as claimed in claim 26, wherein the air-fuel mixture forming means includes a venturi and a fuel discharging nozzle protruding into the venturi and the first and the fourth electrodes are positioned in said fuel discharging nozzle. 
     
     
       28. A fuel control system for a multicylinder internal combustion engine having a main air intake passage, means for injecting fuel into said main air intake passage from an upstream portion thereof, and a plurality of passages connected from the downstream end of said main air intake passage to the combustion chambers of the engine, comprising: means for ionizing the injected fuel in said upstream portion of said main air intake passage;   a plurality of control electrodes, at least one of said control electrodes being disposed in each of said plurality of passages; and   means for selectively biasing each of said control electrodes at different potentials in response to an input signal applied thereto to control the amount of fuel introduced into each of said combustion chambers, thereby controlling the air-fuel ratio of mixture supplied thereto.   
     
     
       29. A fuel control system as claimed in claim 28, wherein said biasing means includes means responsive to an engine operating parameter to apply different potentials depending on the variation of the operating parameter. 
     
     
       30. A fuel control system as claimed in claim 29, wherein said engine operating parameter is the ignition timing of the engine. 
     
     
       31. A fuel control system as claimed in claim 29, wherein said biasing means comprises first means responsive to a predetermined process of each of said combustion chambers, second means responsive to said predetermined process of a specified one of said combustion chambers, and third means for sequentially applying a set of different potentials to said control electrodes in response to said first and second means to enrich and lean the mixture supplied to said combustion chambers in synchronism with each different combustion process. 
     
     
       32. A fuel control system as claimed in claim 28, wherein each of said electrodes is disposed in a position adjacent to the point of connection said main air intake passage and said plurality of passages. 
     
     
       33. A fuel control system as claimed in claim 28, wherein said biasing means comprises a voltage source having first and second terminals and means for selectively connecting said first and second terminals of said voltage source to each of said control electrodes. 
     
     
       34. A fuel control system as claimed in claim 28, further comprising a venturi in said main air intake passage, and wherein said injecting means comprises a nozzle in the vicinity of said venturi, and wherein said ionizing means includes means for electrically biasing said nozzle with respect to said venturi. 
     
     
       35. A method for controlling the air-fuel mixture ratio supplied to each combustion chamber of a multicylinder internal combustion engine having a main air intake passage, means for injecting fuel into an upstream portion of said main air intake passage, and a plurality of passages connected from the downstream end of said main air intake passage to the combustion chambers respectively, said method comprising the steps of: (a) providing a plurality of control electrodes respectively in said plurality of passages;   (b) ionizing the fuel injected into said upstream portion;   (c) detecting a predetermined process in each of said combustion chambers;   (d) detecting said predetermined process of a specified one of said combustion chambers; and   (e) biasing said control electrodes at one of a first and a second potential in response to the steps (c) and (d).   
     
     
       36. A method as claimed in claim 35, further comprising the step of varying the potentials applied to said control electrodes in response to an engine operating parameter. 
     
     
       37. A method as claimed in claim 35, further comprising the step of varying the magnitude of ionization of the injected fuel in response to an engine operating parameter. 
     
     
       38. A method as claimed in claim 35, wherein the step (e) comprises the step of applying said first potential to a predetermined one of said control electrodes and applying said second potential to the remainder of said control electrodes in synchronism with each of said detected process. 
     
     
       39. Arrangement as claimed in claim 1, further comprising a plurality of third electrodes, at least one third electrode being positioned in each of the combustion chambers of the internal combustion engine, and means for supplying said second charge from said electrostatic charging means to each of said third electrodes, whereby the air-fuel mixture in the vicinity of said third electrodes is enriched.